Music as a non-pharmacological intervention for anxiety during extracorporeal shock wave lithotripsy: a systematic review, meta-analysis, and trial sequential analysis of randomized controlled trials.
INTRODUCTION Extracorporeal shock wave lithotripsy (ESWL) is a widely used non-invasive treatment for urinary stones. Nevertheless, procedural noise, discomfort, uncertainty, and repeated shock-wave delivery may cause clinically relevant anxiety. Music has been proposed as an accessible non-pharmacological strategy to improve the patient experience, but previous reviews have reported heterogeneous results and have frequently combined anxiety with pain or audiovisual interventions. We evaluated the association between music exposure and anxiety during ESWL. METHODS MEDLINE/PubMed, Embase, Scopus, the Cochrane Central Register of Controlled Trials, and Google Scholar were searched from inception to March 2026. Randomized controlled trials comparing music with standard care or no music in adults undergoing ESWL were eligible. Anxiety measured using a Visual Analog Scale (VAS) and the State-Trait Anxiety Inventory (STAI) was analyzed separately. Random-effects meta-analyses were performed using mean differences (MDs) with 95% confidence intervals (CIs). Risk of bias was evaluated using Cochrane RoB 2. Leave-one-out sensitivity analyses, Baujat plots, funnel plots, and trial sequential analysis (TSA) were also performed. RESULTS Twelve randomized controlled trials were included in the systematic review. Ten contributed to the VAS analysis and eight to the STAI analysis. Music was associated with lower anxiety measured using VAS (MD -1.01; 95% CI -1.63 to -0.39; I2 = 80.1%) and STAI (MD -4.46; 95% CI -7.10 to -1.81; I2 = 91.2%). Leave-one-out analyses showed that the direction of the pooled estimates was not determined by any single study. However, substantial heterogeneity and possible small-study effects were present. The certainty of evidence was rated as very low for both outcomes. Under the pre-specified assumptions, TSA indicated that the cumulative evidence crossed the trial sequential monitoring boundary, although this finding does not address the risk of bias or inconsistency of the underlying studies. CONCLUSION Music was associated with modest reductions in anxiety scores during ESWL and may be considered a feasible non-pharmacological adjunct. Nevertheless, substantial heterogeneity, methodological limitations, variation in music and analgesia protocols, and very low certainty of evidence limit confidence in the magnitude and clinical relevance of the pooled effects. Additional well-designed trials using standardized interventions and clinically meaningful anxiety outcomes remain warranted.